Spectroscopy

Fourier Transform Infrared Spectroscopy

We acquired a new Thermo-Nicolet iN10MX FTIR with 2D mapping capabilities using a linear array with a space resolution of ~5-10 µm, and detection limits at ppm level for water in geologic materials. This instrument allows mapping and precise measurement minerals and glasses that can be used to determine decompression rates of volcanic eruptions when combined with robust CO₂ measurements determined by Raman spectroscopy.

PI: Esteban Gazel

IR to UV Spectroscopy

The Bruker Vertex 80 is equipped with detectors (MCT, DLaTGS, Si diode, GaP diode) that allow for the collection of spectra with a resolution of up to 0.06 cm-1 with a combined spectral range from the UV to the mid-IR (50000-350 cm-1; 0.2-28.6 μm). The Hyperion 2000 can do a similar range for the absorbance and transmittance of samples sitting on the microscope stage (33000-600 cm-1; 0.3-16.7 μm). Spectra can be obtained from samples inside the Vertex chamber as thin films; with an integrating sphere (8000-350 cm^-1; 1.3-28.6 μm); under the Hyperion microscope 15x objective in reflection, transmission, or emission modes. We are also equipped with a Linkam heating stage to analyze material up to 1500 °C using the full spectral range of the instrument.

PI: Esteban Gazel

Raman micro-spectrometry

The WiTec Alpha 300r is an advanced confocal Raman microscope that combines fast imaging, high spectral sensitivity and spatial resolution with excellent analysis software into a system designed around spectral imaging. The system has a 532-nm laser one spectrometers covering shifts in the visible that allow future blue and red lasers additions if necessary.  Raman shifts within ~100 cm-1 of the excitation frequency can be measured routinely. The system has high confocality and boasts a minimum depth slice of ~350 nm, enabling users to take 2D and 3D spatial maps of Raman intensity over areas as large as several square cm. Using 3D volume mapping of moderately absorbing samples, the Raman intensity can survey to depths of multiple microns into the sample. We also included an internal Ne source that allows to collect Ne lines simultaneously with the data if needed. This allows for a highly precise internal calibration. This instrument allows mapping at high resolution resolution of bubbles and melt inclusion components, while also increasing the analytical resolution for peak fitting.